A two-way stretch fabric prepared by polyurethane elastic fibers has been known. However, the fabric has problems in heat resistance, light resistance, chemical resistance, dyeing property and fungus resistance as disadvantages of the polyurethane material. Further, since the stretching property is based on a rubber-like elasticity, its stretching rate reaches to as high a value as not lower than 400%, but a stress value for the stretching rate when the stretching property is practical in use is rather high and thus it gives a tight clamp of rubber-like elasticity which limits its application.
Further, in order to obtain a two-way stretch non-woven fabric, a non-woven fabric of loose tissue with little enveloping of the fiber coated with a natural rubber latex also is known. However, the non-woven fabric has a low stretching rate lower than 9% and has a disadvantage of forming texture slipage in use and of being broken.
Additionally, a non-woven fabric prepared by a procedure in which a crimping treatment is applied on polyamide fibers, and webs are formed using them, and then they are resin-treated, is known. However, the stretching is limited to the lateral direction and the stretching rate is also as low as lower than 9%.
Japanese Laid-Open Patent Publication No. 168159 of 1974 discloses non-woven fabrics having a high elastic recovery and a soft feeling, which are prepared by point-bonding with a fibrous polymer (C) having a low melting point a web comprising an eccentric sheath & core conjugate fiber produced with two components, 5-sulfo-isophthalic acid copolymerized polyester (A) and polybutyrene terephthalate (B).
On the other hand, side by side conjugate fibers have been used to produce wadding, raw stock for quilting and the like, woven fabrics, knitted fabrics, bulky yarns for handcraft, non-woven fabrics and the like. For example, Japanese Laid-Open Patent Publication No. 80561 of 1980 discloses raw stock for wadding prepared with conjugate fibers in which differences of sulfonic acid group comprised in the polymer are at least 0.4 mol % and low angle scattering strength of X-rays is less than 15, and further discloses in the examples acrylic conjugate fiber produced by a side by side method in which differences of sulfonic acid group are 0.2 to 1.5 mol %. Japanese Laid-Open Patent Publication No. 70012 of 1986 discloses polyester conjugate fibers having a specific heat shrinkage which are produced by eccentrically bonding polyester (A) copolymerized with a metal sulfonate group of 3 to 6 mol % and polyester (B), and further exemplifies a stretch non-woven fabric produced by blending a polyester fiber having a low melting point in the conjugate fiber. However, each of them does not teach a two-way stretch fabric produced by using side by side conjugate fibers.
As described above, a fabric, which has enough two-way stretching ability, a low stress for the stretching rate and further has a stretching property of soft follow-up property, has not been available.
Accordingly, an object of the present invention is to provide a fabric which has a low stress for the stretching rate and has a soft and following-up stretching property and also has an excellent dyeing property in a commercial scale production.